skip to main content
Language:
Search Limited to: Search Limited to: Resource type Show Results with: Show Results with: Search type Index

Impact of blinding on estimated treatment effects in randomised clinical trials: meta-epidemiological study

BMJ (Online), 2020-01, Vol.368 (2), p.l6802-l6802 [Peer Reviewed Journal]

Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to ;Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions. ;Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions 2020 BMJ This is an Open Access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/ . Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License. ;Distributed under a Creative Commons Attribution 4.0 International License ;Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to 2020 BMJ ;ISSN: 1756-1833 ;ISSN: 0959-8138 ;EISSN: 1756-1833 ;DOI: 10.1136/bmj.l6802 ;PMID: 31964641

Full text available

Citations Cited by
  • Title:
    Impact of blinding on estimated treatment effects in randomised clinical trials: meta-epidemiological study
  • Author: Moustgaard, Helene ; Clayton, Gemma L ; Jones, Hayley E ; Boutron, Isabelle ; Jørgensen, Lars ; Laursen, David L T ; Olsen, Mette F ; Paludan-Müller, Asger ; Ravaud, Philippe ; Savović, Jelena ; Sterne, Jonathan A C ; Higgins, Julian P T ; Hróbjartsson, Asbjørn
  • Subjects: Bayesian analysis ; Bias ; Clinical trials ; Clinical Trials as Topic - methods ; Clinical Trials as Topic - organization & administration ; Clinical Trials as Topic - standards ; Epidemiologic Research Design ; Epidemiology ; Humans ; Intervention ; Life Sciences ; Mathematical models ; Meta-analysis ; Mortality ; Observer Variation ; Outcome Assessment, Health Care - methods ; Outcome Assessment, Health Care - statistics & numerical data ; Patients ; Research Design - standards ; Subjectivity
  • Is Part Of: BMJ (Online), 2020-01, Vol.368 (2), p.l6802-l6802
  • Description: AbstractObjectivesTo study the impact of blinding on estimated treatment effects, and their variation between trials; differentiating between blinding of patients, healthcare providers, and observers; detection bias and performance bias; and types of outcome (the MetaBLIND study).DesignMeta-epidemiological study.Data sourceCochrane Database of Systematic Reviews (2013-14).Eligibility criteria for selecting studiesMeta-analyses with both blinded and non-blinded trials on any topic.Review methodsBlinding status was retrieved from trial publications and authors, and results retrieved automatically from the Cochrane Database of Systematic Reviews. Bayesian hierarchical models estimated the average ratio of odds ratios (ROR), and estimated the increases in heterogeneity between trials, for non-blinded trials (or of unclear status) versus blinded trials. Secondary analyses adjusted for adequacy of concealment of allocation, attrition, and trial size, and explored the association between outcome subjectivity (high, moderate, low) and average bias. An ROR lower than 1 indicated exaggerated effect estimates in trials without blinding.ResultsThe study included 142 meta-analyses (1153 trials). The ROR for lack of blinding of patients was 0.91 (95% credible interval 0.61 to 1.34) in 18 meta-analyses with patient reported outcomes, and 0.98 (0.69 to 1.39) in 14 meta-analyses with outcomes reported by blinded observers. The ROR for lack of blinding of healthcare providers was 1.01 (0.84 to 1.19) in 29 meta-analyses with healthcare provider decision outcomes (eg, readmissions), and 0.97 (0.64 to 1.45) in 13 meta-analyses with outcomes reported by blinded patients or observers. The ROR for lack of blinding of observers was 1.01 (0.86 to 1.18) in 46 meta-analyses with subjective observer reported outcomes, with no clear impact of degree of subjectivity. Information was insufficient to determine whether lack of blinding was associated with increased heterogeneity between trials. The ROR for trials not reported as double blind versus those that were double blind was 1.02 (0.90 to 1.13) in 74 meta-analyses.ConclusionNo evidence was found for an average difference in estimated treatment effect between trials with and without blinded patients, healthcare providers, or outcome assessors. These results could reflect that blinding is less important than often believed or meta-epidemiological study limitations, such as residual confounding or imprecision. At this stage, replication of this study is suggested and blinding should remain a methodological safeguard in trials.
  • Publisher: England: BMJ Publishing Group LTD
  • Language: English
  • Identifier: ISSN: 1756-1833
    ISSN: 0959-8138
    EISSN: 1756-1833
    DOI: 10.1136/bmj.l6802
    PMID: 31964641
  • Source: BMJ Open Access Journals
    AUTh Library subscriptions: ProQuest Central
    MEDLINE
Back to results list
INSPIRE LIBRARY - TON DUC THANG UNIVERSITY (84-028) 37 755 057 Feedback
19 Nguyen Huu Tho St. Dist.7, HCM thuvien@tdtu.edu.vn

Copyright © 2017 INSPIRE LIBRARY - TON DUC THANG UNIVERSITY

Searching Remote Databases, Please Wait